[OpenMP][libomptarget] Add support for declare target to clause under unified memory
Summary:
This patch adds support for handling variables under the:
```
#pragma omp declare target to()
```
clause when the
```
#pragma omp requires unified_shared_memory
```
is used.
The address of the host variable is copied into the device pointer just like for the declare target link case.
Reviewers: ABataev, caomhin, grokos, AlexEichenberger
Reviewed By: grokos
Subscribers: jcownie, guansong, jdoerfert, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D63106
git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@363825 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/libomptarget/plugins/cuda/src/rtl.cpp b/libomptarget/plugins/cuda/src/rtl.cpp
index 844afa1..04a3ddc 100644
--- a/libomptarget/plugins/cuda/src/rtl.cpp
+++ b/libomptarget/plugins/cuda/src/rtl.cpp
@@ -448,9 +448,18 @@
DPxPTR(e - HostBegin), e->name, DPxPTR(cuptr));
entry.addr = (void *)cuptr;
- if (DeviceInfo.RequiresFlags & OMP_REQ_UNIFIED_SHARED_MEMORY &&
- e->flags & OMP_DECLARE_TARGET_LINK) {
- // If unified memory is present any target link variables
+ // Note: In the current implementation declare target variables
+ // can either be link or to. This means that once unified
+ // memory is activated via the requires directive, the variable
+ // can be used directly from the host in both cases.
+ // TODO: when variables types other than to or link are added,
+ // the below condition should be changed to explicitely
+ // check for to and link variables types:
+ // (DeviceInfo.RequiresFlags & OMP_REQ_UNIFIED_SHARED_MEMORY &&
+ // (e->flags & OMP_DECLARE_TARGET_LINK ||
+ // e->flags == OMP_DECLARE_TARGET_TO))
+ if (DeviceInfo.RequiresFlags & OMP_REQ_UNIFIED_SHARED_MEMORY) {
+ // If unified memory is present any target link or to variables
// can access host addresses directly. There is no longer a
// need for device copies.
cuMemcpyHtoD(cuptr, e->addr, sizeof(void *));
